Tube door



FIG. 1 is a top, right-side, front perspective view of the tube door;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right-side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a left-side elevational view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines depict unclaimed parts of the tube door, and thus form no part of the claimed design. 

CLAIM The ornamental design for a tube door, as shown and described. 